Roger Ackman, who ran Imperial's legal department in the 1980s until his retirement in 1999, said he hired outside counsel to destroy at least 60 documents relating to company research on smoking and health problems, The Globe and Mail writes.

The testimony is part of a $27-billion class-action suit launched on behalf of Quebec tobacco addicts and smokers against three tobacco companies for denying proven health risks of smoking for decades.

While Mr. Ackman was fuzzy on many details, a 2006 ruling in United States Federal District Court fills in many gaps. The ruling concluded research papers stored in the US, Canada and Australia were shredded to hide damning evidence.

The only remaining copies of many of the papers were stored in the United Kingdom by British American Tobacco, an Imperial affiliate, setting up a series of extra jurisdictional hurdles for plaintiffs – if they became aware the research papers existed.

According to the judge in the case, the shredding was done to protect U.S. tobacco company Brown & WIlliamson in its own lawsuit.